Instructions for Learners
You will be given 45 minutes to read Part A and make notes.
Part A contains the set task brief you need to prepare for Part B, Section 1.
Read the set task brief carefully.
You should use the space provided at the end of Part A to make notes.
You will use the set task brief in Part A and your notes to complete the set task in Part B, Section 1.
You must return Part A and Part B at the end of the examination.
The teacher/tutor and/or invigilator must not give you feedback during the time given to read and
make notes for Part A.
P74564A 3
Turn over
, Set Task Brief for Part B, Section 1
A trainee scientist wants to develop a new washing liquid. The washing liquid will use enzymes to
break down fat stains on clothing.
The trainee scientist is investigating the optimum temperature for lipase to break down fat in milk.
The fat in milk is broken down by lipase to fatty acids and glycerol. The fatty acids affect the pH of the
lipase‑milk mixture.
Phenolphthalein is an indicator of pH. Phenolphthalein is colourless at pH values below 8.2, turns pink
at pH 8.2 and gets darker to pH 10.
The trainee scientist produces this draft report of their investigation.
Draft report
Title
An investigation into the effect of temperature on lipase activity.
Aim
To measure the time taken for the fat in milk to break down at different temperatures.
4 P74564A
You will be given 45 minutes to read Part A and make notes.
Part A contains the set task brief you need to prepare for Part B, Section 1.
Read the set task brief carefully.
You should use the space provided at the end of Part A to make notes.
You will use the set task brief in Part A and your notes to complete the set task in Part B, Section 1.
You must return Part A and Part B at the end of the examination.
The teacher/tutor and/or invigilator must not give you feedback during the time given to read and
make notes for Part A.
P74564A 3
Turn over
, Set Task Brief for Part B, Section 1
A trainee scientist wants to develop a new washing liquid. The washing liquid will use enzymes to
break down fat stains on clothing.
The trainee scientist is investigating the optimum temperature for lipase to break down fat in milk.
The fat in milk is broken down by lipase to fatty acids and glycerol. The fatty acids affect the pH of the
lipase‑milk mixture.
Phenolphthalein is an indicator of pH. Phenolphthalein is colourless at pH values below 8.2, turns pink
at pH 8.2 and gets darker to pH 10.
The trainee scientist produces this draft report of their investigation.
Draft report
Title
An investigation into the effect of temperature on lipase activity.
Aim
To measure the time taken for the fat in milk to break down at different temperatures.
4 P74564A
